Rezumat
CZU 678.073:661.481
DOI https://doi.org/10.5281/zenodo.3522281
In this paper, the structure and dielectric properties of polymer nanocomposites based on polyvinildenfluorid (PVDF) and iron nanoparticles have been investigated. Scanning electron microscopy studies show that, with increasing the volume fraction of iron particles, the supramolecular structure of the polymer changes and the size of the particles in the polymer increases (45–130 nm). It was demonstrated that the dielectric permittivity of nanocomposites based of PVDF + Fe varies similarly to pure polymer matrices at low concentrations of Fe nanoparticles; hoevev, for high concentrations, a different dependence was observed. It was found that from 100 Hz the value of dielectric permittivity begins to decline and does not change practically during a further increase of frequency. This is due to the delay interfacial of polarization at high frequencies compared to the frequency of the field, thus weaking the polarization process. In addition, the temperature dependence of the dielectric permittivity, dielectric loss tangent, and the values of the specific resistivity of nanocomposites based on PVDF + Fe were studied. The dielectric permittivity has been observed to decline from 373 K in volumes of 5% and 10% of Fe nanoparticles in a polymer matrix, which is explained by an increase in temperature. The disturbance of the regularity of the dipoles therefore decreases of the polarization of the nanocomposites.
Keywords: polyvinildenfluorid, nanocomposite structures, polymer, dielectric permittivity, specific resistivity.